Stop motion for sewing machines and the like



May 15, 1928. 1,669,912

F. A. REECE STOP MOTION FOR SEWING MACHINES AND THE LIKE Filed March 13, 1925 2 Sheets-Sheet 1 \nvenTor. FronKlinA.F?eece 'byWMk/M ATTys'.

May 15, 1928. 1,669,912

F. A. REECE STOP MOTION FOR SEWING MACHINES AND THE LIKE Filed March 13, 1925 I 2 Sheets- Sheet Fig. v Fig.4. 3 634 85 3 :24 23/ 38 8 lnvenToT: FmnKlin A. Reece ATTys.

Patented May 15, 1928.

UNITED STATES PATENT OFFICE.

FRANKLIN .A REECE, OI BROOKLINE, MASSACHUSETTS, ASSIGNOR TO THE REECE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORA- TION OF MAINE.

l STOP MOTION FOR SEWING MACHINES THE LIKE.

Application filed March 13, 1925; Serial No. 15,412.

This invention relates to stop motions for sewing machines and the like and particularly to a stop motion of the type illustrated in United States Patents No. 367,063, July 23, 1887, and No. 713,764, November 18th, 1902. These patents show a driving and stopping'mechanism which comprises a driving pulley having a shoulder and mounted on a shaft, a clutch dog pivotally mounted on a hub fast to the shaft and adapted to engage the shoulder of'the pulley, said dog being urged toward this operative position by a spring, and a clutch-disengaging mem her which is normally latched in its inoperative position but which when released is moved into its operative position to engage the tail of the dog and thereby swing the latter about its pivot and release it from the shoulder of the driving pulley, said-clutchdisengaging member co-operating with the dog after it has been released to bring the shaft to rest.

The machine shown in said patents is a buttonhole sewing machine which includes stitch-forming mechanism and work-holding means having a movement relative to each other and in said machine the latch is re leased at the proper time in the cycle of movements by such relative movement.

In actual practice it sometimes happens that this release of the latch occurs just as the tail of the clutch dog is passing the clutch-disengaging member and when this condition obtains there is the possibility that said clutch dog will wipe by the clutch-disengaging member thus causing the latter to rebound or causing what is termed a fly over.

It is one of the objects of my present invention to provide an improvement in this type of stop motion which will eliminate any possibility of such a rebound or fly over and which will invariably ensure the proper stopping of the shaft when the machine is released.

The features wherein the invention resides will be pointed out in connection with the following description of a selected embodiment of my invention.

Fig. 1 is a side view of a buttonhole sewing machine having my improvements ap- As intimated above the present invention is Sl1OWl1 dS it might be applied to a buttonhole sewing machine of the type illustrated in the above-mentioned Patent No. 713,764.

Said sewing machine is provided with a bed plate 1 carrying work-holding means in the form of work clamps 2. It is also provided with the usual stitch-forming mechanism which includes a needle 3 operative above the work and also includes an under threadhandling mechanism operating beneaththe work but which is not herein shown, said stitch-forming mechanism being mounted on a head 4 that is herein shown as movable back and forth upon the bed plate 1, this movement providing the necessary relative movement between the stitch-forming mechanism and work-holdingmeans to accomplish {he1 stitching along the edges of the button- The stitch-forming mechanism is operated said dog having a nose 10 adapted to engage a shoulder 11 formed on the pulley. The dog is acted upon by a spring 12 which tends to throw it into its operative position with its nose in engagement with the shoulder 11 and when the parts are thus engaged the clutch is operative and the shaft 5 will be driven from the driving pulley 6. The

clutch isreleased at proper times by means of a clutch-disengaging member 13 which is ill) adapted to engage the tail 14: of the clutch dog, the engagement of said tail with the clutch-disengaging member swinging the dog about its pivot 8 and thereby withdrawing the nose 10 from the shoulder 11.

This clutch-disengagin member 13 is carried by a rocking member 15 fast on the shaft 16 and said shaft has fast thereto an arm 17 which is acted on by a spring is, said spring tending to move the clutch-disengaging member forwardly into its opera tive position. The clutch-disengaging member is retained in its inoperative position while the clutch is in engagement by means of a latch member 19 pivoted at 20 to the head l and having a shoulder :21 adapted to engage a projection on the arm 17. So long as the latch engages the projection 22 as shown in fullulines Fig. 3 the clutchdisengaging member-is retained in its inoperative position out of the path of movement of the tail 14 of they clutch dog as shown in F ig..5, (said path being shown by the dotted circular line 41 in Fig. 5), and the clutch will, therefore, remain operative. \Vhen, however, the latch 19 is released from the projection 22 then the spring 18 tends to swing the clutch-disengaging member 13 forwardly into its operative position, in which it is in the path of movement of the tail is of the dog 7. e

The clutch-disengaging member is provided with an arm 23 having a roll 21 at its end and the hub Sis formed with a cam surface 25.situated in line with the roll 24. This cam surface has a high concentric portion 26 and a low portion :27. The high portion 26 has such radial dimensions that when the roll 24 rests against it as shown, in Fig. 4, the clutch-disengaging member 13 will be held just out of the path of movementof the tail 1410f the do, as shown by its intermediate position in Fig. 5. When. however, the low portion 27 comes under the roll 24 then the clutch-disengaging member is moved forward into its operative positionby the spring 18 and is brought into the pathof movement of .the tail 14 of the dog as shown by the left hand dotted line position Fig. 5. i

Thelatch 19 is released from the lug 22 by the movement of the head 1, all as shown in:thehbove-mentioned patent, and for this purpose the bed frame is provided with a rib or abutment 28 whichis adapted to en age a screw 29 carried by the lower end .of the latch 19 as the head 4 moves forward,

it being understoodthat the latch is pivotally mounted on the head and moves therewith.

The parts are so adjusted that the screw 29 will engage the abutment 28 just before the stitching is completed on the buttonhole and the feeding movement which takes place during'the formation of the last few stitches will gradually swing the latch 19 from the full to the dotted line position Fig. 3 and thereby release it. The final release of the latch, however, may take place when the shaft 5 and the clutch dog is in any angular position. If the release takes place when the shaft and clutch dog are in the position shown in either Fig. 3 or 4' then the first movement of the clutch-releasing member due to the action of the spring 18 will bring the roll 2-1 against the high concentric por- (ion 26 of the cam 25 and as the cam turns and the low portion 27 passes under the roll 2 1 the clutch-releasing member will have a further inward movement bringing it into the path of the tail 14: so that the dog will be released and the shaft 5 brought to rest.

It sometimes happens, however, that the final release of the latch will occur when the low portion 27 of the cam has partially passed the roll 24 and when thetail 14 of the dog is justabout opposite the clutch releasing member 13. If therelease occurs at this time the clutch-releasing member, when it moves forward, is apt to strike the end of the tail of the dog andif this occurs ill) the clutch may not be released and the impart is likely to. cause the clutch-releasing member to rebound, thus allowing what is termed a fly over.

It is one of the objects of mypresent invention to provide a novel device for pre venting this from happening and I accomplish this by providing'an abutment or stop which functions temporarily to arrest the clutclrreleasing member when the latch is released and which holds it arrested during a partial rotation of the shaft and until the dog has just passed the clutch-releasing member and then to allow the clutch-rcleasing member to move forwardly into a position controlled by the high portion 20 of the cam 25 as shown in Fig. 1. This abutment or stop member is shown as a lever 30 pivoted at, 31 to an arm or bracket 32 which is secured 'to the head 4. said lever being acted on by a spring 33 which tends to move it downwardly. This lever 30 carries a roll 34 which operates on a cam surface 35 formed on the hub 9. The cam surface 35 has the low portion 36 extending throughout the greaterportion of its periphery and the relatively short high portion 37. As the cam rotates, therefore, the lever 30 has an up and down movement. it being'moved upwardly by the high portion of the cam and moved downwardly by the spring 33, the latter keeping the roll in engagen'ient with the cam. j j i i The arm 15 of the clutch-releasing memher isprovided with an extension 38 which is i position, as shown in full lines, Fig. '3, the

end 39 of said arm is slightly separated from the extension 38 as shown in Fig. 3. This is the position which the parts assume while the machine is operating and during thethis position the clutch-disengaging member is still outside the path of movement of the tail 1 1 of the dog 7. This release of the latch 19 may occur when the shaft 5 is in any angular position and assuming that itoccurs when the shaft is in approximately theposition shown in Fig. 3 then it will be understood that the clutch-disengaging member/will be moved forward by the spring 18 until the extension38 engages the end 39 of the stop arm 80. The clutch-disengaging member will be held in this position by the stop arm 30 while the shaft continues its rotation and until the high part 37 of the cam surface 35 passes under the roll 3-4:, as shown in Fig. 4. \Vhen this happens then the arm 30 is lifted above the extension 38 and the clutclrdisengaging member is again released. It will then move forward under the influence of the spring 18 to bring the roll 24 against the cam surface 25 as seen in Fig. 4 and in this position the extension 38 is beneath the end. 39 of the stop arm 30 so that when the stop arm moves downward ly again it will rest on the top of the extension 38. WVhen thereafter the low portion 27 of the cam 25 passes under the roll 24 then the clutch-disengaging member is permitted to move forwardly into. operative position to disengage the clutch.

The cams 35 and 25 are rigid with each other and have such a relative position that the high portion 37 of the cam 35 will always operate to raise the stop arm 30 just after the low portion 27 of the cam 25 has passed by the roll 24, as shown in Fig. 4. Hence the clutch-disengaging member is. always released from the arm 30 at a predetermined point in the rotation of the shaft 5 so that when the clutch-disengaging member moves forward after its release from the arm 30 the roll 24 will always engage the cam 25 at approximately the same point.

The parts are preferably so timed that the release of the clutch-disengaging member from the arm 30 will take place just after the low portion 27 of the cam 25 has passed the roll 24 so that the shaft 6 will have about one-half or three-quarters of a revolution to make between the time that the clutch-disengaging member is released from the stop arm 30 and the time when the low portion27 of the cam comes under the roll 24. The arm, 30, therefore, and its co-operat-ing cam 3 5brings the final movement of the clutchdisengaging member into absolute timed re lation with the rotation of the shaft 6 and this precludes the possibility ofthe fly over as above described.

I claim: h

1. In a sewing maehinehaving stitch forming mechanism and work-holding means movable relative to each other, the combination with said stitch-forming mechanism and work-holding means, of a clutch for operating the stitch-forming mechanism, a clutch-disengaging member, a latch to hold the clutch-disengaging member in inoperative position, means to release the latch by the relative movement between the stitchforming mechanism and workholding means, and two devices, both operating in timed relation with said clutch but acting successively to control the movements of the clutch-disengaging member into its operative position after it is unlatched.

2. In a sewing machine having stitch forming mechanism and work-holding 'means movable relative to each other, the

combination with said stitch-forming mechanism and work-holding means, of a driving shaft for operating the stitch-forming mechanism, a clutch by which the shaft is driven, a clutch-disengaging member, a latch to hold the clutch-disengaging member in, its inoperative position, means to release the latch by the relative movement b-ctweenthe stitchforming mechanism and Work-holding means, a spring tending to move the clutchdisengaging member into its operative position, a stoparm mounted separately from the clutch-disengaging member and operative in one position to engage said member and restrain the spring-impelled movement thereof, said stop arm being capable ofmovementrelative to said clutch-disengaging member, and means operative when' said shaft .is in a predetermined angular position to move said stop arm into inoperative position in which it is out ofengagement with the clutch-disengaging member.

3. In a sewing machine having stitchforming mechanism and work-holding means movable relative to each other, the combination with said stitch-forming mechanism and work-holding means, of a driving shaft for operating the stitch-forming mechanism, a clutch by which the shaft is driven, a clutch-disengaging member, a latch to hold the clutch-disengaging member in its inoperative position, means to release the latch by the relative movement between the stitch-forming mechanism and work-holding means, a spring tending to move the clutch-disengaging member into its operative position, a stop arm pivotally mounted Ill independent of the clutch-disengaging member,sa1dstop arm when in operative position restraining the spring-impelled move engage the latter afterit has been released and maintain it in its inoperative position, and means rotating in timed relation with the shaft and acting on the stop 'member to move it into a position to free the clutchdisengaging member when the shaft occupies a predetermined angular position.

5. In a device of the class described, the combination with a shaft to be driven, of a clutch for driving the shaft, a spring-actuated clutch-disengaging member, a latch to hold said member inoperative, means operat ing in non-timed relation to the rotation of the shaft to release the latch, whereby the angular position of 'the shaft at the time of the release of the latch is indeterminate, a vibrating stop member movable in timed relation to said shaft into and out of operative position, said stop member when in operative position maintaining the clutch-disengaging member inoperative, and when in inoperative position releasing the clutchdisengaging member.

(3. In a sewing machine having stitchforming mechanism and work-holding means movable relative to each other, the combination with said stitch-forming mechanismand work-holding means, of a shaft for operating the stitch-forming mechanism, a clutch for dri ving the shaft, a spring-actuated clutch-disengaging member, a latch to-hold said member in inoperative position, means to disengage the latch by therelative movement between the stitch-forming -mechanism and the work-holding'meansya the canrwhen the shaft is in a predetermined angular position.

7. In a sewing machine, 'the'combination withstitch-forming mechanism and workholding means movable relative to each other, of a shaft for operating thestitch-form ing mechanism, a clutch for driving the shaft, a spring-actuated clutch-disengaging member, a latch to hold said member inoperative, means to release the latch by the relative movement between the stitchiorming mechanism and work-holding means, and two successively acting devices, both operating in timed relation with said shaft to control the spring-actuated movement of the clutclmlisengaging member into its operative position so thatsaid movement is eli'ectedin two stages.

8. In a sewing machine, the combination with stitch-forming mechanism and workholding means movable relative to each other, of a Sllil ft for operatingthe stitch-forming mechanism, a clutch for driving the shaft, a spring-actuated clutch-disengaging member, a latch to hold said member inoperativel, means to release the latch by the relative movement between the stitch-forming mechanism'and work-holding means and two successively-acting devices, one of which is mounted independently of the clutch-disengaging member and both of which operate in timed'relation with the rotation of the shaft to control the spring-actuated move its operative position so thatsaid movement is effected in two stages.

In testimony whereof, I. have signed my name to this specification.

FRANKLIN A. REECE.

ment of the clutch-disengaging member into 

